I have an '82 F150 351 C6. In the spring of 2024, I replaced the mechanical fuel pump with a Carter mechanical since the old one was leaking around the block. The block seal was bad. Shortly after, I replaced both tanks, senders, rubber hose, selector switch, and metal lines. I also rebuilt the 2150 and put on a new filter. I had an issue with her shutting off and low power for a month until I realized it was the cheap gas. I now only run ethanol-free fuel, and she runs like a top. This past week, she was shutting down, hesitating, and in what seemed like a limp mode on newer vehicles ( I know it does not have one, but it gives you an idea of my issues). I pulled the lines and checked the hoses and selector switch for issues. It does it on both tanks leading me to the pump. She will normally idle fine. Sometimes, she acts like she is starving at an idle, but most often running at higher speeds. It is like the carb bowl empties faster than the pump can fill. Here is my question. I know the newer mechanical pumps are Chinese junk. How long do they last? Does ethanol fuel eat away or ruin the diaphragm? I am probably going to install a quality inline pump. Any suggestions on a brand or model?
I am also considering selling her once I get her fuel issue resolved if you know anyone who might be interested. I'd like to start on my Wagoneer.

 

Is the fuel filter at the carb clean ?

You may want to pull the inlet line off the pump and blow back through it. Make sure the lines doing have any crap in them.

 

I'd recommend getting an inline fuel pressure gauge and install it right before the carb filter. It helps with this scenario.
You will see if it's getting the proper psi to the carb or not. It could still be something besides the pump but, from time on this forum. It seems mechanical pumps today seem hit and miss?

 

BTW, nice looking truck.

 

Yes it is clean. I can clearly see the screen.

 

With the engine running, can you see gas flow through the filter ?

 

Yes, it looks like enough but obviously can't see it going down the road when she really acts up. Carb was also rebuilt last spring. It's been great and runs too good when there is sufficient fuel.

 

When you rev the engine with the hood open, can you see more fuel pump into the filter ? See if you can hold the rpm's at say 2500-300 and see if the filter keeps getting supplied.

We need to verify the pump is putting out enough flow. I pressure gauge would be nice if you could T it into the line after the filter and tape it to the wiper blade and go for a drive.

I'm just trying to come up with ideas.

 

A fuel problem will not just "shut off" going down the road.
Now if you said "like it runs out of gas and shuts off and you have to crank it a lot before it restarts" then I would say a fuel problem.

You said you replaced the rubber hose did you replace ALL the rubber hoses?
At the senders, at the tank switch valve and main line to pump?

I am going to say replace the ICM for the DS II with top of the line one.
They have been known to cause different problems leading up to "just shutting off".
If it dose not fix the problem give it to the new owner when you sell it.

Me I would not sell the pickup as much as I love AMC / Jeeps.
What year is it? Guessing a 360 & TH400 auto transmission?
I was given one that was heading to the junk yard but I needed the transmission and later the motor for my AMC Javelin drag car.
Dave ----

 

I suspect the fuel is getting too hot. Especially after you had to get rid of the ethanol fuel and it helped it. I don't know why, but some vehicles will just not run on this newer fuel. My Bronco II was like that and after many attempts to cure it, a small electric pump mounted on the frame rail the near the fuel tank cured it.